Three main options are suggested regarding charges: first, charges may be specified in a statement of work; second, they may be agreed by the parties in writing on an ad hoc basis; and third, the charges may be calculated on a time-spent basis.
Other important provisions of the T&Cs include:
a space for providing a definition of the services, together with details of the standards (e.g. reasonable skill and care) that the services must meet;
payment provisions, detailing when payments must be made, how they must be made, and the consequences of a failure to pay;
general warranties concerning the services;
limitations and exclusions of liability, protecting both or one of the parties;
provisions regarding the termination of contracts, and what happens after termination; and
general boilerplate provisions.